Google's beloved web-based email client has always been ripe for third-party design customization (we've always been partial to the Gmail Redesigned skin in Better Gmail, for example), but now Gmail is officially riding the interface customization train by offering 30-some new themes to spice up your inbox. Keep reading for a screenshot tour of the cool new offerings.

Ninja

Graffiti

Planets

Candy

Shiny

Mountains

Terminal

You can check out some of the other new options in the preview grid below.

Unfortunately I still don't see the Themes tab in my Gmail settings, but Google is an expert of the slow rollout, so we can all expect them sometime in the next few days. I'm partial to the ascii/Terminal theme, though it's probably a touch on the impractical side. Other than that, a lot of the offerings actually look really nice—especially compared with some of the lame duck skins Google offers in iGoogle. Let's hear which themes you like best—and whether or not they're actually enabled in your accounts yet—in the comments. Thanks Mark!